塔河油田碎屑岩储集层泥浆侵入带的测井响应

Well Logging Response from Filtrate-Invaded Zone in Clastic Reservoir in Tahe Oilfield

新疆塔河地区西南部东河塘组为碎屑岩储集层,油层和水层的深、中电阻率均呈负差异,利用典型井的双感应和阵列感应测井资料进行了实例分析。根据泥浆侵入理论,将泥浆侵入因素归纳为静态因素和动态因素,分析了泥浆侵入机理。对典型井在不同孔隙度、含水饱和度、混合水电阻率情况下的地层电阻率进行数值计算。结果表明,泥浆高侵特征是由于泥浆电阻率高、物性差等引起地层电阻率的增加量大于含水饱和度高或含油性差引起地层电阻率的减小量。因此,不能简单根据电阻率的差异性或是否存在低阻环带直接判断油水层,而需要结合泥浆滤液矿化度和地层水矿化度差异、物性、原油流动性等因素进行综合判断。

The Donghetang formation in southwestern Tahe oiifield in Xinjiang is a elastic reservoir which appears negative distinction of deep and medium resistivity between oil and water zones. The dual induction and array induction logging data from typical wells are analyzed. The factors of mud filtrate invasion are classified as static factor and dynamic factor. The mechanism of mud filtrate invasion is studied. The calculation of formation resistivities in the case of different porosity, water saturation and mixed water resistivity shows that the negative distinction of resistivity is resulted from that the increase of formation resistivity caused by high mud filtrate resistivity and poor petrophysical property is larger than the decrease of formation resistivity caused by high water saturation and poor oil-bearing property. It is concluded that oil and water layers should not judged only by difference between deep and medium resistivities or by presence of lower resistivity zone, besides, combining the difference between mud filtrate salinity and formation water salinity with petrophysical property, oil mobility, etc., should be required.